Indeed.
Generally there are very few cases where you can actually make a relevant conclusion regarding the correctness of a decision just based on looking at the superficial damage visible. GSP's post-Hendricks face is a good example of superficial damage that's completely irrelevant in terms of judging the actual fight, yet it's often posted as 'proof' that GSP, in fact, lost the fight, when all that truly mattered was the scoring of R1.
Then there are more acceptable cases where the level of post-fight superficial damage corresponds with the actual amount of punishment absorbed, like, say, Mousasi vs Jardine. In that particular case, Jardine's post-fight face told the actual story of the fight, and provided reasoning for why Jardine's time on top should've actually been scored for Mousasi, who was in complete control and dealing significant enough offense off of his back to cause this: